Tile over rigid insulation.

Hey guys, Im a first time poster and I am seeking some important information for finishing my basement. There are no problems with flooding and water. It is cold down there in the winter and I want to warm up the floors. So i am thinking of putting down a 1 inch thick rigid closed cell rigid insulation over the concrete floor. Then I was going to put down a vapour barrier and tuck tape both the vapour barrier and the rigid insulation seams. Over this I am thinking of putting 3/4 " tounge and groove OSB. I was then going to Tapcon a perimiter of 1" x 2" (to match the height of the rigid insulation) boards on the concrete floor in the rooms and screw the plywood sheeting to those boards, over top of the rigid insulation. The catch is I want to put tile down. I dont know if I can tile over 3/4" OSB which has been tapconed through to the concrete. I was planning on fastening the plywood through the rigid foam insulation to the concrete floor using tapcons. I know a tile substrait shouldnt move more than a 1/16th of an inch so the grout dosnt crack. I was woundering if there was anyone who has done this and what they would do different or if they have some suggestions. I was thinking of also putting 1 x 2 straping every 16 in to fasten to the concrete and then fasten the plywood to the boards. But then there is the issue of the insulation not being continuous. Any suggestions?

Advertisement

what should I use?

Most grouts that I use say that there should be no more than a 16th of an inch movement in a subfloor. Idealy I would prefer less. And I dont know if I should use plywood or OSB. OSB is cheaper and I think it dosnt expand and contract as much as Plywood. Is plywood better for a substraight? Whenever I tile I leave a 1/8" gap between sheeting and screw it to the floor and use glue. But that is over plywood subfloors. I really want to know if this is possible, or if there is a better option for tiling over and insulated substraight. Thanks.

Most of the tilers I know use plywood and flexible grout in that type of situation. You can get plywood with insulation bonded to it.
I'm only a bricklayer though, so I would check it out with a local tiler.

Most grouts that I use say that there should be no more than a 16th of an inch movement in a subfloor.

I'm still trying to learn here. Could you give me the names of the grout products you use routinely that says that on the label? I would like to see and read it for myself. So what are the brand names and what are the product names?